Diaphragm horn



May 5, 1936. F. VON volcsTLJuDER 2,039,694

DIAPHRAGM HORNA Filed March le, 195e Patented vd5, 1193@ UNET@ STATES DIAPHRAGM HRN Frederick Von Voigtlandcr, Adrian, Mich., as-

signor to Schwarze Electric Company, Adrian, Mich., a corporation o? Michigan Application March i6, i936, Serial No. 69,1@5

s crains. .(ci. ire- Mai This invention relates to horns of the diaphragm type.

This invention has utility when incorporated in mountings for horn diaphragms, more especially as adapted independently of centering thereof.

Referring to the drawing:

Fig. l is a fragmentary side view of an embodiment of the invention adapted to a sound signal or horn, say in motor vehicle use;

Fig. 2 is a side View of the diaphragm for the horn of Fig. 1 on the side away from the projector;

Fig. 3 is a section on the line 11i- IE Fig. 2; and

Fig. l is a fragmentary detail on an enlarged scale, showing features of the mounting seat and diaphragm for the horn.

Bracket l is shown having eye 2 through which extends externally threaded bushing 3 engaging internally threaded portion l of casing member 5. Nut t on this threaded bushing il positions the bracket l for holding the device in the desired assembly position in a motor vehicle. This casing member 5 has port 'i at which is located fitting t3 having therein plunger 9 operable by control il), say from the dash of the motor vehicle. This control lll, as opened, permits communication byduct l l having tting assembly l2, with intake i3 to the internal combustion motor of this motor vehicle. It thus follows that manual operation of the control l0 aiects communication as by suction, reduced pressure or Vacuum from the intake i3 to the interior chamber portion Ml of the casing member l5.

The bushing t has central opening l in which is press itted. projector i6 desirably additionally anchored by soldering, brazing or welding. Between this projector l@ and the chamber lll, the casing member 5 has annular seat ll, spaced by clearance i3 from the root of the internally threaded portion it. The seat ll is of ring form and toward the projector l from the chamber lli. The casing member 5 is provided with outward annular seat i9, and therefrom inwardly extending annular seat 2li separated by ledge 2l as a seat concentric to the seat i9. From this ledge 2l, parallel to the seat 20 and concentric thereof is seat 22. Bolts through yieldable washers 2li and openings 25 in companion or complementary casing member 25 assemble this member 26 with the casing member 5 as these bolts 23 enter threaded openings Zi in the casing member 5. Casing member 26 has ange 28 snugly tting on the seat l@ and radially inwardly extending portion 2@ therefrom snugly engaging the seat 20. In practice, these casing members 5 and Z6 are desirably of zinc or other die-cast elements of snug fitting relation. As thus assembled, there is provided an 5 inwardly open channel seat 30 of U-shape in cross section by this seat 22, ledge 2l and the inwardly extending section of the portion 29. Centrally, this casing member 26 is provided with closure 3l concentric with the projector i6. 10

Diaphragm 32, say of thin sheet steel as tempered Swedish spring steel, has peripheral notches 33 for clearance of the bolts 23. Inasmuch as these bolts 23 are overlapping in their extent from the seat 2G to the seat 22, that is l5 partially across the ledge 2l, these notches serve to anchor the disk or diaphragm 32 against rotation relatively to the casing. There is such normal clearance not only at these notches 33 but in peripheral region 3G that there may be 20 some expansion and contraction as well as eccen-l tric shifting of the diaphragm 32 in its snug slip nt in the seat d.

However, this seat 3d, in practice, is one not designed to accommodate other than radial shift- 25 ing as to the diaphragm 32. This means that there is not appreciable axial shifting at the periphery. This thin Swedish sheet steel flexible disk 32 has central opening 35, through which extends sleeve 36 having terminal shoulder 3l., 30 The sleeve. 36 as herein adopted, has rigid washers 3S, 39, adjacent the shoulder 3l. The washer 39 is spaced from direct contact with the sheet metal diaphragm 32 by Washer ill), desirably of a fiber base as paper or linen impregnated say with 35 phenol condensation product. This results in a tough, slightly compressible washer, locating in its periphery flex region il on such side of the diaphragm 32. Different diameter, similar stock, compressible washer l2 is located on the opposite 40 side of the diaphragm 32, and as held by washer i3 and nut Ml, locates a flex region i5 on the opposite side from the ex region il and spaced therefrom, in this instance concentrically inward. There is, accordingly, minimizing of chances for shear and a lengthening of the life of the diaphragm.

in this internally threaded sleeve 3S, there is located externally threaded bolt fit?, having thereon lock nut ill. This bolt it protrudes beyond 5,0 the shoulder di and there has spun or riveted head lll spaced by compressible washer i9 from minor valve disk till. The minor valve disk Ell on the opposite side has compressible Washer 5l held spaced v:from larger diameter portion or 55 shoulder by metal washer 52. 'I'he washers 4U, 42, 49, 5I, are of similar compressible material. The minor secondary disk is located to cooperate with the seat II. The adjustment for such predetermined cooperation is through this bolt 46 mounting the minor disk to be positioned by the major diaphragm 32.

The axial adjustment between thev disks is determined by releasing lock nut 4'I, and with a tool such as a screw driver, acting on notch 53 for rotating to increase or decrease the distance between these two disks 32 and "50. There' may be occasion to position this minor disk 50 for `normal nicety of clearance as to the seat II in determining tonal response. To this end, ready access to chamber 54 is had by removal of closure bolt 3l. As this adjustment is determined, the lock nut 41 is re-set andthe closure plug or short bolt 3l is re-positioned to close this chamber 54.

In operation in the instance herein described with sub-atmospheric pressure, the disk 50 which, as a valve, normally approaches closure position at the seat I1, vibrates as to suchseat due to the reduction of air pressure in" the chamber I4, with the resultant exing of the larger diaphragm 32 toward the projector I6 because of `the greater area of this diaphragm 32 in the reduced pressure chamber I4. 'I'he opposite side of the diaphragm 32 is in chamber 54 normally at atmospheric pressure, but the air therein is trapped so that there is effective dampening of the action of this sound signaling device in the vibratory response effected from the flexible disk 32 as acting upon the minor flexible disk or valve 50.

Each of these disks is desirably of thin sheet steel and subjected to slight\exing. The bolt 46 is'connecting means spacing the disks 50, 32, from each other approximately the distancebetween the planes of the seats Il, 30. The compressed washers dissipate strain and stress from fatigue. Furthermore, they avoid erosion attack or weakening for such attack in the central regions of exure. There is also avoidance of shock to the diaphragms due to the reversals of the oscillating,1 system comprising the minor or valve disk 50 and the major or actuator disk 3.2.

'In the operations hereunder, there is air column disturbance and frequency to give a good, clear air tone which has a range of regulation for penetration and carrying powers. Furthermore, this pneumatic response, even though suction, 'is uniformly effective under ranges of temperature affecting the contraction and expansion of the disks for such do not produce any buckle in either disk due to their location for peripheral clearance. Furthermore, the power vdisk 32 has such snug seating in the seat 30 that, while there is accommodation against binding or disk distortion allowing the disk to center itself or to shift itself as to its center, there iseffective packing of the chamber I4 as exposed to the reduced pressure against such exhausting the chamber 54. This effective packing follows herein due to the effective seating and holding of the edges of the disk 32.

` The air trapped 1n the chamber 54 by the diaphragm 32 is an eiective dampening factor. Untoward Vbalance of air therein may seep through the seat 30 at non-operating conditions of this signal. However, during operation, the diaphragm 32 is peripherally effectively sealed at its self-centered floating position. In practice, a desirable thickness gage for this diaphragm 32, when of tempered Swedish spring steel, may

Acillated in operation are to a degree fixed in the completed structure, there is an elective factor for tone adjustment in varying the distance between the valve 50 and the diaphragm 32. A

In practice, this disk 50 seemingly is actually in a; sealing position on the seat I'I for a nicety and clarity for tone adjustment. Y v

What is claimed and it is desired to secure by Letters Patent is:

1. A sound producing signal comprising a castion in signal operation, said seat and diaphragm providing a seal at said seat and chambers in the casing, said chambers being spaced from communication therebetween by said diaphragm in signal operation, said diaphragm being normally of less diameter than the ring diameter from the depth of the seat and with slip-fit coaction therewith at non-operation of the'signal, a projector from the casing of the signal having communication therewith from the chamber controlled by said. diaphragm, and signal actuating pneumatic means connected to said chamber for bringing said diaphragm to sealing position in said seat upon operation of the signal.

2. A sound producing signal casing providing an inwardly open channel ring forming a seat, an eccentrically shiftable centrally oscillatable diaphragm having its peripheral edges at said seat, said casing and diaphragm having a seal at said seat during-signal operation providing two chambers spaced from communication therebetween by said diaphragm, said diaphragm being normally of less diameter than the ring diameter from the depth of the lchannel seat to permit eccentric shifting of the diaphragm at non-operation oi'hsaid signal, `and a projector from the casing, said diaphragm upon operation of the signal, controlling communication between one of said chambers and the projector with said diaphragm in sealing position at said seat.

3. A sound producing signal comprising a casing providing a seat of ring form in a common plane and of inwardly open U-cross section, and a centrally oscillatable diaphragm having its peripheral edges held in said seat against oscillation in signaloperation, said seat and diaphragm providing a seal at said seat and chambers in the casing, said chambers being spaced from communication therebetween by said diaphragm in signal operation, said diaphragm being normally of less diameter than the ring diarnlatable diaphragm having at signal operation a peripheral seal at its edges in said seat, and normally with radial clearway of the diaphragm as to the seat, said diaphragm being peripherally notched, and casing-member-assembly bolts in said 'notches restraining the diaphragm against rotation relatively -to the casing, with slip-t coaction between the diaphragm and seat at nonoperation of the signal.

5. A pneumatic sound producing signal casing providing a seat, a diaphragm having its edges pneumatically sealing with said seat in signal operation, saidl diaphragm having normally a radially-free periphery in said seat at non-operation of the signal, said diaphragm in signal operation forming with the seat and `casing two chambers spaced from communication by said diaphragm, and a projector and signal actuating pneumatic means each adapted to have communication with one of said chambers and said means bringing said diaphragm to sealing position in said seat.

6. A pneumatic sound producing signal casing providing a chamber having a pair of independent axially-spaced, annularly-continuous seats each in a different plane, a pair of flexible disks one for each seat and normally in the plane of such seat, one of said disks and seats cooperating to provide a pneumatic seal for said chamber with said disk forming a closure s ide for the chamber as a lcomplete partition, and rigid connecting means between and centrally spacing the disks approximately the distance betweenl the planes of said seats, said seats cooperating to limit longitudinal movement of said connecting means in operation to the range of central portion oscillation of said disks, said casing in the peripheral planes of said disks being of greater diameter than said disks to permit limited eccentric shifting of the disks and connecting means relatively to said casing.

.7. A sound'apparatus sheet metal diaphragm having a central opening therethrough, a relatively compressible washer about said opening on one side of said diaphragm, a different diameter, relatively compressible washer about the opening on the other s`ide of said diaphragm, and rigid means clamping said washers, thereby determining dissimilar flexing regions upon opposite sides of said diaphragm.

8. A sound producing signal casing comprising a pair of opposing intertting members providing an inwardly-open U-shaped cross section ring forming a seat, an eccentrically shiftable diaphragm peripherally in said seat, said diaphragm being peripherally notched, an'd casing-memberassembling bolts in said notches restraining the diaphragm against rotation relatively to the casing, said diaphragm being held at said seat against clatter in the sound operation of said signal.

FREDERICK VON VOIGTLANDER. 

